DE102018222610A1 - Electromagnetic actuator - Google Patents

Abstract

An electromagnetic actuating device (10) comprises a sleeve (34), an armature (32) arranged radially inside the sleeve (34) and an electromagnetic coil (16) arranged radially outside the sleeve (34), the armature (32) on has a first anchor face (48) at one end and a second anchor face (50) at the opposite end. It is proposed that the sleeve (34) on or in the sleeve wall (52) has a channel (54) extending along the longitudinal direction (46) of the sleeve (34), by means of which a flow connection between the armature end faces (48, 50) is formed.

Description

State of the art

The invention relates to an electromagnetic actuating device according to the preamble of claim 1.

In automatic car transmissions, hydraulically operated clutches are used to change gear, the hydraulic pressure on the clutches being set by hydraulic slide valves. Gate valves can be operated via a pilot valve (pilot control) or directly via an electromagnetic actuator. In order to obtain damping, such actuation devices are filled with oil, with oil being displaced from the shrinking space in front of the armature when the armature of the actuation device is being moved and pumped into the enlarging space behind the armature via an overflow channel. This pumping process dampens the armature movement. Since gear oil has a high air absorption capacity, in practice there is the problem of a fluctuating oil level in the armature space, which makes constant damping difficult. The overflow channels are designed, for example, as bores in the armature, as in DE 10 2005 030 657 A1 shown. In addition to complex production, this can lead to a reduced magnetic flux and reduced magnetic forces due to the reduced cross-section of the armature.

Disclosure of the invention

The problem underlying the invention is solved by an electromagnetic actuating device with the features of claim 1. Advantageous developments of the invention are mentioned in the subclaims.

According to the invention, an electromagnetic actuating device is proposed which has a sleeve (flux sleeve), an armature (magnet armature) arranged radially inside the sleeve and an electromagnetic coil arranged radially outside the sleeve. The anchor can be guided directly or indirectly within the sleeve, for example by a sliding fit. By activating the electromagnetic coil, the armature can be displaced along its longitudinal direction in the electromagnetic actuation device. This corresponds to the classic arrangement of an electromagnetic actuator.

The anchor has a first anchor face at one end and a second anchor face at the opposite end. The sleeve has on or in the sleeve wall a channel which extends along the longitudinal direction of the sleeve and by means of which a flow connection (hydraulic connection) can be established or formed between the anchor end faces.

When the armature moves, the channel (overflow channel) in the sleeve allows oil to flow over between the end faces of the armature, largely avoiding any impairment of the magnetic circuit. It is not necessary to form overflow channels in the armature. This simplifies production, with weakening of the magnetic circuit being largely avoided. This contributes to an inexpensive magnet construction.

The sleeve (flow sleeve) can have a substantially cylindrical cross section. It goes without saying that “essentially cylindrical” means that the sleeve can comprise collars, shoulders, grooves, changes in wall thickness, etc., but is generally cylindrical or tubular. The sleeve can be fixed in a rotationally fixed manner in the actuating device. Armature, sleeve and electromagnetic coil are arranged in an (axial) overlap with each other. The electromagnetic actuating device can in particular be an electromagnetic actuator or an electromagnetic actuator (“electromagnet”).

According to a further development, the armature can be designed channel-free, in particular free of overflow channels. In other words, the armature can be free of bores or grooves that form overflow channels. This contributes to cost-effective production and a comparatively large effective cross-sectional area of the armature.

According to a further development, the sleeve can be formed by punching and rolling (sleeve is punched and rolled). The base material of the sleeve can be punched out and the sleeve can be brought into its essentially cylindrical shape by rolling. This is a simple and inexpensive manufacturing process, with thinner wall thicknesses of the sleeve than, for example, in the case of machining.

According to a further development, the sleeve can be made of magnetically conductive, unalloyed steel, in particular with a carbon content of less than 0.15 mass percent (carbon content <0.15%). This is a magnetically highly conductive material, which contributes to a high magnetic efficiency.

According to a further development, the sleeve can have an open cross section with a longitudinal slot (ring segment), the free ends of the sleeve wall enclosing the longitudinal slot between them and thus delimiting the channel in the circumferential direction, ie towards the channel sides. Of the The channel thus runs through the longitudinal slot, which laterally delimits the channel. This makes it easy to create a channel in the sleeve (flow sleeve). In particular in the case of production by punching and rolling, the longitudinal slot can be formed directly during production (butt joint between the free ends of the sleeve wall). A complex additional process for the production of the channel (overflow channel) can thus be avoided. The channel can be delimited radially inwards by the armature, in particular by the outer surface of the armature. The channel can be delimited radially outwards by the electromagnetic coil, in particular by the coil body of the electromagnetic coil (for example the inner jacket).

According to a further development, the channel or the longitudinal slot can have a first channel cross-section that tapers axially in sections to a second channel cross-section. By changing the channel cross-section, the damping properties can be influenced using simple design means. If the sleeve is punched and rolled, the contour of the free ends of the sleeve wall can be easily created. The first channel cross-section can have a cross-sectional area of 2 percent or more (≥2%) of the (pumping) armature cross-sectional area. This cross-sectional requirement preferably applies to 60 percent or more of the length of the channel (≥ 60% of the channel length). This avoids an excessive damping effect. The second channel cross-section can have a cross-sectional area of 0.5 to 1.5 percent (0.5% - 1.5%) of the (pumping) armature cross-sectional area. This cross-sectional requirement preferably applies to 40 percent or less of the length of the channel (40 40% of the channel length), the sum of the channel lengths together being 100% of the channel length, that is to say together corresponding to the channel length (sleeve length). This enables ("aperture-shaped") temperature-independent damping to be achieved. The channel can be the longitudinal slot and the channel cross-sections can be slot cross-sections.

According to a further development, a pole core can be provided which is axially adjacent to the armature and which has a groove in a section, in particular an annular section facing the armature, which is aligned with the channel of the sleeve. The groove in the pole core contributes to an improved oil flow between the anchor faces. The groove thus favors the oil flow at the end of the armature facing the pole core, at which the armature can be guided through the pole core. Such guidance can take place through a recess in the annular section of the pole core, into which the armature engages and on which the armature is guided. An actuating element, in particular an actuating pin, can be introduced into the pole core. The pole core itself can be formed in one piece, for example as a turned part.

Alternatively or additionally, an inner sleeve (magnetic sleeve) can be provided, which is arranged radially between the sleeve (flux sleeve) and the armature, the inner sleeve in its sleeve wall having an axial slot which extends over an axial section of the inner sleeve and which communicates with the channel of the Sleeve (flow sleeve) is aligned. The course of the magnetic force can be influenced by means of the inner sleeve. The usable lifting work of the electromagnetic actuating device can be increased. The axial slot is formed in particular on that end of the inner sleeve which faces the first end face (pole core side). This contributes to an improved oil flow between the anchor faces. The inner sleeve can be formed by stamping and rolling. Optionally, the inner sleeve can be latched at the butt ends (latching). Independently of this, an axial slot (open joint) can also be formed at the other end of the inner sleeve.

This favors the oil flow between the anchor faces. In addition, joining of the inner sleeve with other components is favored. The inner sleeve can be made of the same material as the sleeve (flow sleeve).

Alternatively or additionally, a pole core can be provided which has a separate pole sleeve which is arranged radially outside the pole core and surrounds the pole core at least in sections, the pole sleeve having a groove in a section facing the armature, in particular an annular section, which is in contact with the channel the sleeve is aligned. This contributes to an improved oil flow between the anchor faces. In addition, a comparatively inexpensive production can be achieved since the pole core and pole sleeve can be produced separately, for example as stamped parts.

According to a development, the sleeve (flow sleeve) can be fastened in a rotationally fixed manner in the actuating device such that the channel is above the armature in the direction of gravity or below the armature in the direction of gravity. The information regarding the direction of gravity relates to the installation position of the electromagnetic actuation device, for example on an automatic car transmission. The sleeve is installed in the actuator in a rotationally fixed manner and has no possibility of rotating during operation. It is therefore possible to orient the channel so that it is at the lowest point (in the direction of gravity below the anchor) and even a small oil level provides the necessary damping. For applications where damping should be low, the duct can be placed at the highest point (in the direction of gravity above the anchor) so that even a small air cushion in the anchor space ensures that the damping is reduced to a minimum.

According to a further development, the sleeve (flow sleeve) or the inner sleeve on its inner circumference for guiding the anchor can have a glass fabric film coated with PTFE (polytetrafluoroethylene) at least in sections, preferably completely. The coated glass fabric film as a bearing element for the anchor enables positive sliding properties to be achieved.

As an alternative to this, the sleeve or the inner sleeve on its inner circumference and / or the armature on its outer circumference, at least in sections, preferably completely, have a magnetically non-conductive coating, in particular a nickel layer or a nickel-phosphor layer. This also allows positive sliding properties to be achieved.

The electromagnetic actuating device can have further components. For example, the electromagnetic actuation device can have a housing (magnet housing) in which the components of the actuation device are accommodated. On one end face, in particular on the end face facing the pole core, the actuating device can be closed by an end piece, which can be a flux disk. On the opposite end, in particular on the end facing away from the pole core, the actuating device can be closed by a cover (magnetic cover). To connect the electromagnetic actuating device, an electrical contact can be provided which is electrically connected to the electromagnetic coil, for example a socket section attached to the housing or a plug section. An actuating element, for example an actuating pin, can be inserted into the pole core and is guided through a passage formed concentrically in the pole core. The actuating element can have a shaft section and a radially widened head section with which it rests on the inside of the passage on the pole core.

• 1a,b einen schematischen Schnitt durch eine elektromagnetische Betätigungseinrichtung (1a) und in einer vergrößerten Ansicht eine Hülse der Betätigungseinrichtung (1b);
• 2a-c eine Ausgestaltungsmöglichkeit der Hülse der Betätigungseinrichtung aus 1b in einer perspektivischen Ansicht (2a) und mehreren Schnittansichten (2b und 2c) der unterschiedlichen Kanalquerschnitte;
• 3a,b einen schematischen Schnitt durch eine Ausgestaltungsmöglichkeit der elektromagnetische Betätigungseinrichtung (3a) und in einer vergrößerten Ansicht eine Zwischenhülse der Betätigungseinrichtung ( 3b); und
• 4a,b einen schematischen Schnitt durch eine Ausgestaltungsmöglichkeit der elektromagnetische Betätigungseinrichtung (4a) und in einer vergrößerten Ansicht eine Polhülse der Betätigungseinrichtung (4b).

Possible embodiments of the invention are explained below with reference to the accompanying drawings. Show it:

• 1a, b a schematic section through an electromagnetic actuator ( 1a) and in an enlarged view a sleeve of the actuating device ( 1b) ;
• 2a-c an embodiment of the sleeve of the actuator 1b in a perspective view ( 2a) and several sectional views ( 2 B and 2c ) the different channel cross sections;
• 3a, b a schematic section through an embodiment of the electromagnetic actuating device ( 3a) and in an enlarged view an intermediate sleeve of the actuating device ( 3b) ; and
• 4a, b a schematic section through an embodiment of the electromagnetic actuating device ( 4a) and in an enlarged view a pole sleeve of the actuating device ( 4b) .

An electromagnetic actuator carries in 1a overall the reference symbol 10 . Such an electromagnetic actuator 10 is used, for example, in transmission technology in motor vehicles, in particular for controlling a clutch of an automatic transmission. For this purpose, for example, a hydraulic valve which is in 1a only schematically by one with the reference symbol 12th provided box is indicated by the electromagnetic actuator 10 operated.

The electromagnetic actuator 10 has a housing 14 in which the components of the electromagnetic actuator 10 are arranged. The electromagnetic actuator 10 has an electromagnetic coil 16 on that over a bobbin 18th and a winding 20 disposes. On a first face 22 is the housing 14 by means of an end piece 24th closed, which can be a river disc. On a second face 26 is the housing by means of a cover 28 sealed, which is a magnetic lid 28 can act. On the housing 14 is also an electrical contact 30th provided with the electromagnetic coil 16 is electrically connected.

The electromagnetic actuator 10 also has an anchor 32 (Magnetic armature), a sleeve 34 (River sleeve) and a pole core 36 on. The pole core 36 has a central passage 38 on, through which an actuator 40 is guided (actuating pin) on the hydraulic valve 12th works. The actuator 40 can have a shaft section 42 as well as a radially expanded head section 44 exhibit.

The anchor 32 is radially inside the sleeve 34 arranged. Radially outside the sleeve 34 is the electronic coil 16 arranged. The sink 16 , the anchor 32 and the sleeve 34 overlap each other along the axial direction 46 at least partially. The anchor 32 has a first anchor face at one end 48 (the pole core 36 facing) and on opposite end a second anchor face 50 on (from the pole core 36 turned away).

The sleeve 34 points to or in the sleeve wall 52 one along the length 46 the sleeve 34 extending channel 54 by means of which a flow connection (hydraulic connection) between the anchor faces 48 , 50 is formed. The pole core 36 is at anchor 32 axially adjacent and has the anchor in one 32 facing, in particular annular, section 53 a groove 55 on that with the channel 54 the sleeve 34 flees. The anchor 32 moves when the coil is activated 16 along the axial direction 46 , for example in the direction of the first end face 22 , with a reset of the anchor 32 For example, by applying force to the actuating pin 40 can be done. Due to the axial movement of the armature 32 results in the channel 54 an oil flow that means arrow 56 is illustrated. The anchor 32 itself is channel-free (free of overflow channels), so it has no bores or grooves.

The sleeve 34 is so rotatably in the actuator 10 attached that the channel 54 in the direction of gravity above the anchor 32 (installation position of the actuating device 10 ). In embodiments not shown, the sleeve 34 so rotatably in the actuator 10 be attached to the channel 54 in the direction of gravity below the anchor 32 located.
The sleeve 34 is in 1b shown individually, where the channel 54 is clearly visible. The sleeve 34 is formed by punching and rolling, the sleeve 34 is thus first punched and then brought into its essentially cylindrical or tubular shape by rolling. The sleeve 34 is made of magnetically conductive, unalloyed steel, in particular with a carbon content of less than 0.15 mass percent (<0.15%).

The sleeve 34 has an open cross section with a longitudinal slot 58 on (butt joint), with the free ends 60 , 62 the longitudinal slot between them 58 include and thus the channel 54 in the circumferential direction, than to the sides. In other words, the sleeve 34 as a ring segment with a longitudinal slot 58 educated. A canal boundary 54 can go radially inward through the anchor 32 respectively. A canal boundary 54 can go radially outwards through the coil 16 , especially through the bobbin 18th respectively.

The sleeve 34 points on its inner circumference 57 to guide the anchor 32 at least in sections, preferably completely, a glass fabric film coated with PTFE 59 on. Positive sliding properties can be achieved. Alternatively, the sleeve 34 on their inner circumference 57 or the anchor 32 on its outer circumference 61 at least in sections, preferably completely, have a magnetically non-conductive coating, in particular a nickel layer or a nickel-phosphorus layer.

2nd shows an embodiment of the sleeve 34 with one channel 54 whose channel cross section changes over the sleeve length. So the channel points 54 a first channel cross section 64 on (cf. 2 B) which is in an axial section of the sleeve 34 to a second channel cross section 66 is tapered (cf. 2c ). The cross-sectional areas can be selected as described above. In the present exemplary embodiment, the area with the second channel cross section 66 axially between two areas with a first channel cross section 64 arranged (cf. 2a) . Will the sleeve 34 formed by punching and rolling, can be by appropriate design of the contour of the free ends 60 , 62 the changing channel cross-section can also be easily manufactured.

3rd shows an embodiment of the electromagnetic actuator 10 that are largely the same as in the 1 and 2nd described embodiment corresponds (same or functional same elements have the same reference numerals). In the design according to 3rd is an inner sleeve 68 (Magnetic sleeve) provided radially between the sleeve 34 and the anchor 32 is arranged. The inner sleeve 68 points in their sleeve wall 70 one over an axial section of the inner sleeve 68 extending axial slot 72 on the one with the channel 54 the sleeve 34 flees. The axial slot 72 is on the first face 22 (pole core side) facing end of the inner sleeve 68 educated. At the other end of the inner sleeve 68 is another axial slot 74 trained who with the channel 54 the sleeve 34 flees. The inner sleeve 68 is formed by stamping and rolling. Optionally, the inner sleeve 68 at the butt ends 73 be latched (latching 75 ). Optionally, the pole core 36 a groove 55 (see. 1 ) exhibit. The groove 55 is present for the establishment of the flow connection between the anchor faces 48 , 50 not mandatory and can therefore be omitted. On the inner circumference of the inner sleeve 68 can be used to guide the anchor 32 At least in sections, preferably completely, a glass fabric film coated with PTFE may be provided (not shown). Alternatively, the inner sleeve 68 on their inner circumference or the anchor 32 on its outer circumference 61 at least in sections, preferably completely, have a magnetically non-conductive coating, as described above.

4th shows an embodiment of the electromagnetic actuator 10 that are largely the same as in the 1 and 2nd described embodiment corresponds (same or functionally identical elements have the same reference numerals). In the design according to 4th is a polar core 36 provided a separate pole sleeve 76 has the radially outside of the pole core 36 is arranged and the pole core 36 surrounds at least in sections (multi-part design; cf. 4a) . The pole sleeve 76 lies with its inner circumference 78 on the outer circumference 80 of the pole core 36 on. The pole sleeve 76 points at least in one of the anchors 32 facing section 53 a groove 55 on that with the channel 54 the sleeve 32 flees. The groove 55 can optionally be used as the entire length of the pole sleeve 76 extending longitudinal slot 55 be trained. The pole sleeve 76 is individually in 4b pictured.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102005030657 A1 [0002]

Claims (10)

Electromagnetic actuating device (10), having a sleeve (34), an armature (32) arranged radially inside the sleeve (34) and an electromagnetic coil (16) arranged radially outside the sleeve (34), the armature (32) being attached to one End has a first anchor face (48) and at the opposite end a second anchor face (50), characterized in that the sleeve (34) on or in the sleeve wall (52) extends along the longitudinal direction (46) of the sleeve (34) Has channel (54), by means of which a flow connection between the armature end faces (48, 50) is formed. Electromagnetic actuator (10) after Claim 1 , characterized in that the armature (32) is channel-free, in particular free of overflow channels. Electromagnetic actuating device (10) according to one of the preceding claims, characterized in that the sleeve (34) is formed by stamping and rolling and / or in that the sleeve (34) is formed from magnetically conductive, unalloyed steel, in particular with a carbon content of less as 0.15 mass percent. Electromagnetic actuating device (10) according to one of the preceding claims, characterized in that the sleeve (34) has an open cross section with a longitudinal slot (58), the free ends (60, 62) of the sleeve wall (52) between them the longitudinal slot ( 58) enclose and thus limit the channel (54) in the circumferential direction. Electromagnetic actuating device (10) according to one of the preceding claims, characterized in that the channel (54) has a first channel cross section (64) which tapers axially in sections to a second channel cross section (66). Electromagnetic actuating device (10) according to one of the preceding claims, characterized in that a pole core (36) is provided which is axially adjacent to the armature (32) and which has a groove (55) in a section (53) facing the armature (32) ) which is aligned with the channel (54) of the sleeve (34). Electromagnetic actuating device (10) according to one of the preceding claims, characterized in that an inner sleeve (68) is provided which is arranged radially between the sleeve (34) and the armature (32), the inner sleeve (68) in its sleeve wall ( 70) has an axial slot (72) which extends over an axial section of the inner sleeve (68) and which is aligned with the channel (54) of the sleeve (34). Electromagnetic actuator (10) according to one of the Claims 1 to 5 or 7 , characterized in that a pole core (36) is provided which has a separate pole sleeve (76) which is arranged radially outside the pole core (36) and surrounds the pole core (36) at least in sections, the pole sleeve (76) in one The armature (32) facing section (53) has a groove (55) which is aligned with the channel (54) of the sleeve (34). Electromagnetic actuating device (10) according to one of the preceding claims, characterized in that the sleeve (34) is fastened in a rotationally fixed manner in the actuating device (10) in such a way that the channel (54) is located above the armature (32) in the direction of gravity or below it in the direction of gravity the anchor (32). Electromagnetic actuating device (10) according to one of the preceding claims, characterized in that the sleeve (34) or the inner sleeve (68) on its inner circumference for guiding the armature (32) at least in sections, preferably completely, a glass fabric film (59) coated with PTFE. and / or that the sleeve (34) or the inner sleeve (68) on its inner circumference and / or the armature (32) on its outer circumference at least in sections, preferably completely, has a magnetically non-conductive coating, in particular a nickel layer or Nickel-phosphor layer.

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